Hi Everyone: I spoke to marc schwartz privately about my problem and he suggested using "make clean" to clear out my original configure results from before I ran the configure command using the --enable-R-shlib. So I ran that and started over and fortunately that solved my problem. So I was able to build R from source and include the shared library option. And Rstudio works now also. Thanks to Marc and whomever else read about my confusion !!!!! [[alternative HTML version deleted]]